Yrkesveiledning for aksjeroboter


Høyesterett avgjorde med knappest mulig flertall at to daytradere som manipulerte Timber Hills aksjerobot frifinnes. Det var nære på at roboter fikk en lukrativ opsjon i det norske aksjemarkedet. To av fem dommere mente at børsservere burde beskyttes mot seg selv.

Det bør være både lovlig og ønskelig at dårlige aktører utnyttes. Dersom loven gir generell beskyttelse til irrasjonelle tradere, ville det resultere i et stadig mindre velfungerende marked. Konsekvensen blir mer uforutsigbare kurssvingninger, dyrere kapital og mindre investering i norske arbeidsplasser. Likevel skriver mindretallet:

“En aktør vil vanligvis raskt forstå at en slik måte å handle aksjer på som er programmert for roboten, ikke kan opprettholdes fordi den kontinuerlig vil resultere i tap. Vår sak gjelder en programfeil som ikke lar seg korrigere som følge av irrasjonelle disposisjoner uten at dette blir oppdaget av de som har ansvaret for roboten.”

Mindretallet mener altså at en skal behandle menneske og maskin ulikt. Når en robot dummer seg ut over tid, så bør altså regelen være at det er den menneskelige motparten som opptrår uredelig. Det er sannsynligvis riktig at Timber Hill ikke klarte å korrigere galskapen fordi ingen hos dem oppdaget det, men ansvaret for det kan vel ikke plasseres andre steder enn hos Timber Hill selv?

Det burde være helt opplagt at aktørene i markedet må behandles likt uavhengig av om hjernen består av silisium eller hjerneceller. Konsekvensen av å beskytte enkelte investorer mot egne feil blir et dysfunksjonelt marked uansett hvem som beskyttes.

Når en megler med pølsefingre taster feil vil meglerhuset normalt selv stå for tapet. Slik må det også være for roboter. Dersom mindretallets syn hadde fått gjennomslag vil en algoritmehandler kunne saksøke sine motparter for ulovlig manipulasjon fordi hennes strategi slo feil. Slike gratis opsjoner bør høyesterett være forsiktige med å dele ut.


Nå falt retten heldigvis ned på riktig side, men vi fikk ingen prinsipiell avgjørelse. Dommen var også med knappest mulig margin, og flertallet var i tvil. Slik burde det ikke vært. De tiltalte manipulerte ikke markedet, men de utnyttet en dårlig programmert robot.

I figuren ser vi kursutviklingen som fikk Oslo Børs til å slå alarm. Salgs og kjøpskursene har variert innenfor et lite intervall på kr. 3,75, eller 6,4 % av prisen. Dette er en helt normal differansen mellom kjøps og salgskurs  (“spread”) for lite likvide aksjer på Oslo Børs. Spread på opp til 50 % kan forekomme. Roboten har imidlertid tilbudt en spread på bare 1,3 %, hvilket er oppsiktsvekkende lavt for en såpass lite likvid aksje. Roboten og de tiltalte ble i liten grad forstyrret av andre. Det mest sannsynlige er derfor at roboten sørget for en kunstig lav spread, og at prisen har svingt innenfor det som normalt skulle vært spreaden for denne aksjen. I så fall kan det ikke under noen omstendighet være snakk om markedsmanipulasjon.

I det hele tatt fremstår det som underlig at frifinnelsen ikke er klarere. Alle dommerne var enige om at de tiltalte har brutt verdipapirhandelloven § 3-8. I så fall bør loven eller forskriftene endres. All aktivitet som bidrar til et mer effisient marked bør i utgangspunktet være lovlig. Utilstrekkelige og irrasjonelle aktører bør ikke lovbeskyttes. Slike aktører forsvinner bare dersom ufornuft og lemfeldighet svir på bunnlinjen. Det oppnår man ikke ved å straffe dem som avdekker det.

I følge mindretallet burde disiplinering skje ved at Finanstilsynet varsles om at det er en stakkars robot der ute som ikke klarer seg så bra. Det er nok ikke mange aktører på Oslo Børs som gidder det. Det må lønne seg å identifisere og utnytte de svakeste i markedet. Roboter som ikke takler det bør finne seg noe annet å gjøre.

A reply to David Beckworth

If potential GDP is what the CBO says it is, then the U.S. economy seems to be stuck in a rut. Proponents of NGDP targeting generally believe this to be the case. They also believe that were the Fed to adopt a credible NGDP target right now (with the NGDP path targeted back to its original path), then this NGDP path would become self-fulfilling. Moreover, they believe that the transition path back to normality would mostly take the form of RGDP growth (with perhaps a temporary blip up in the inflation rate).

I wish I could believe this too. But before I can, I have to find out what combination of logic and evidence underlies this belief. David Beckworth, a strong proponent of NGDP targeting, has kindly directed a reply to my query here. I'd like to offer a quick reply to the defense that he offers.

Theory

David quickly outlines two creditor-debtor problems that a NGDP target would help overcome.
The first problem is restoring the expected relationship between creditors and debtors that prevailed prior to the economic crisis. This is the 'risk sharing' problem recognized by David Andolfatto that a price level or strict inflation target cannot address. A NGDP level target would solve this problem by restoring nominal incomes to their expected pre-crisis paths when debtors signed their nominal debt contracts.
This is the "fairness" issue that talked about in my previous post here. In that post, I suggested that this problem may not be so significant because the price-level seems to be pretty close to its pre-crisis path (at least, if one draws the log linear trend beginning in 1990). But maybe I am missing something because evidently this "is a problem that price-level targeting cannot address." I presume this means that what is needed (given the current price-level) is more RGDP--and more RGDP in the form of greater employment, not productivity. Sure, but how is a nominal target supposed to increase RGDP? And what does restoring RGDP have to do with this "risk-sharing" argument? Of course creditors would like to see their unemployed debtors get back to work and service their debt. This has nothing to do with risk-sharing, as far as I can see.
The second problem is that there is a massive coordination failure among creditors now. Creditors could increase their spending to offset the debtor's drop in spending as the latter deleverages. The reason creditors have not--non-bank creditors are sitting on money assets while bank creditors are destroying them as they are acquired from the deleveraging debtors--is because they are uncertain about future economic activity. These actions by creditors create an excess demand for money or, equivalently, a shortage of safe assets.
David is not being as careful with his language as he should be: he cannot be anywhere near certain that the coordination failure he alludes to actually exists. It is only one of many different interpretations of current events. (An interpretation to be taken seriously, but not stated as if it were obviously true, and the reader obviously dense should he/she not see its veracity. Sorry, just a pet peeve of mine.)

As David knows, I have a lot of sympathy for the "asset shortage hypothesis" (I have written about it here, for example). In fact, any model that has a limited commitment friction that gives rise to debt constraints has a version of this idea embedded in it (this includes all New Monetarist models). The policy prescription coming out of these models is to expand the supply of "high quality" assets to meet the shortage. (Note, however, I have not seen anyone employ sticky nominal debt in these frameworks--would be worth exploring). The most obvious candidate here are U.S. Treasuries, which are used extensively as collateral in repo arrangements and as stores of value. Precisely how the Fed could improve this situation by removing these assets from the market (replacing them with assets that are roughly equivalent -- zero interest cash) needs to be spelled out more clearly. (David possibly has in mind the purchase of private assets, but this is not generally permitted under the Federal Reserve Act. In any case, why not have the Treasury issue bonds to finance the same purchases? Not sure what any of this has to do with a NGDP target).

Evidence
Okay, so what is the empirical evidence that a higher level of NGDP would make a difference now? The most obvious answer is that those advanced economies currently doing the best are the ones where aggregate nominal spending has remained on or near its pre-crisis trend. Case in point is Germany.
It is true that Germany largely escaped the world recession. But was this because agents around the world believed that German NGDP would not depart significantly from its path? Or was it because Germany had no real estate boom/bust episode? This is not evidence that stable NGDP prevents a crisis; it is evidence that avoiding a crisis prevents a decline in NGDP. We need to establish a direction of causality here, before making strong claims about what is happening.
A final but important piece of evidence is FDR's very own QE program in 1933. He had publicly called for the price level to return to its pre-crisis trend and then backed up the rhetoric with a devaluation of the dollar (relative to gold). As Gautti Eggertson shows, this policy dramatically altered expectations and sparked a robust recovery in 1933. This implicit price level target of FDRs was no different than a NGDP level target in this case.
Well, O.K. Although, I'm not sure one would want to compare the decline in the price-level in the early 1930s with what just happened recently; again; see the diagram here.
 
More theory
A NGDP level target would do the same today. It would commit the Fed to buying up as many assets as needed to restore aggregate nominal spending to some pre-crisis trend. Just the expectation of the Fed doing that may itself cause the market to do much of the heavy lifting.
The Fed is currently restricted to purchasing U.S. government bonds and agency debt. As such, the Fed has control over the composition of the total U.S. government debt outstanding (the composition between low-interest cash and higher-interest bonds). Under present conditions, I do not think that this composition matters very much (though I could be wrong). Perhaps David is urging Congress to expand the set of securities available for open market operations? If so, does he see any potential political problems with that?  (The answer should be "yes")

And what about this idea that the expectation of higher NGDP itself bringing about its own fulfillment? I know that Nick Rowe has gone on about this here and elsewhere. I think I'll need a separate post to investigate this claim.

In the meantime, here's a question for the NGDP proponents. I think that most people might agree that the Fed has built up a big stock of reputational capital designed to anchor a 2% inflation target. It may not be the perfect policy rule, but most societies around the world could only wish for such credibility in their monetary authorities. What if the Fed decides to adopt the proposed NGDP target, and fails? What then? What does that do to Fed credibility? Have you worked it out? Or does the solution concept you employ always rely on a self-fulfilling rational expectation?

There is something else. Whether we like it or not, policymakers are not indifferent to the composition of NGDP.

Adopting a NGDP target implies that policymakers can commit to (say) a 5% NGDP growth rate. But what if inflation turns out to be 4% and RDGP growth turns out to be 1%? (Or how about 7% inflation and -2% RGDP growth?) A credible NGDP target implies that policymakers remain committed to the 5% NGDP growth rate. But ask yourself this: Do you really believe that policymakers would leave policy unchanged in this circumstance? 

Is higher inflation really the answer?

A lot of people, including those who favor NGDP targeting, want the Fed to raise the rate of inflation; at least, temporarily. Three questions immediately come to mind: [1] What is the theoretical mechanism linking economic prosperity to the rate at which nominal prices rise; [2] Exactly how is the Fed, given the tools at its disposal, supposed to generate higher inflation under current economic circumstances; and [3] What is the evidence to support the belief that more inflation will reduce unemployment (or increase real GDP)?

There are so many different views out there that it's hard for me to keep track of them all. My last couple of posts dealt with the idea of a NGDP target, and it's close cousin, a price-level target. I'm no expert in the area, but if I understand the logic correctly, the idea is for the Fed to reverse what was a sharp and unanticipated decline in the price-level that occurred in late 2008. The presumption is that because debt is denominated in nominal terms, an unexpected permanent decline in the price-level path increase the real value of the stock of outstanding nominal debt. In turn, this imposes a real burden on all debtors, including households with mortgages and the government sector.

There seem to be two aspects to the "price level" surprise shock. First, there is a "fairness" issue. The shock evidently resulted in a redistribution of wealth from debtors to creditors, and it is only fair that this wealth transfer be reversed. (And since the Fed was the agency responsible for letting the price level drop, it should do the undoing -- even if the same might be accomplished by the fiscal authority). Second, there is an "efficiency" issue. Somehow, this wealth transfer has manifested itself as "deficient aggregate demand." I am not exactly sure how this last part works--maybe somebody can enlighten me (in a language that I can understand--a mathematical model!).

In any case, I am not entirely sure I can believe in the quantitative importance of this mechanism. The prescription presumes a sharp and persistent decline in the price-level path, something that I have trouble seeing in the data. In particular, the follow diagram plots the (log) PCE price-level for the U.S. since 1990; the red line is a (log) linear trend. According this data, we are essentially back on the original price-level path (I think the same roughly holds true when the price-level is measured by the CPI or the GDP deflator).



Of course, the "wealth channel" I described above is not the only way in which higher inflation might stimulate economic activity. Here is Paul Krugman for example: Krugman: Fed Should Tolerate More Inflation to Reduce Unemployment.  
"The main thing the Fed can do is promise that they will be very slow to step on the brakes, that as the economy recovers that they will let inflation rise, not to high levels, but to 3 or 4 percent from two percent," Krugman suggested. "That would move the markets quite a lot. It would lead people who are making plans to think that sitting on cash is not a good idea.
I have no doubt that people would think that sitting on cash is not a good idea. The question is: how would people seek to transform their cash holdings? Krugman seems to think that people will want to go out and spend the cash on goods and services. But what if they instead decide to buy gold or Caribbean real estate? There is also the possibility that nominal rates might rise (perhaps not one for one) with higher expected inflation via a Fisher effect, leaving the real return on "safe haven" assets relatively unchanged. Who really knows what might happen?

At the same time, one has to ask how the move to a higher rate of inflation might affect different members of society. Those on fixed nominal incomes are likely to suffer; at least, in the short run (or however long it takes to index those incomes to the higher inflation rate). What about those who have no bank accounts--those people who rely on cash transactions--the poorest segment of the population? This could, in principle, be rectified by cash disbursements to those deemed to be in need, but...well, good luck with that.

And, in any case, just how is the Fed supposed to engineer this smooth ride up from 2% to 4% inflation? Jim Hamilton has a nice post today explaining why it might not be as easy as people generally think it might be; see here: Should the Fed Do More?

I haven't even touched on my third question here, the one dealing with the inflation-unemployment relationship (for long-run evidence, see the data in here). So many questions, so little time...

NGDP Targeting: Some Answers

I want to thank everyone who replied to my previous blog post NGDP Targeting: Some Questions. It will take me some time to digest all of the information sent to me. In the meantime, let me report on a few of the answers I received.

First, some background information. I do not believe that sticky nominal prices or wages matter (at least as far as explaining years of sub par recovery dynamics). I explain why here: The Sticky Price Hypothesis: A Critique. Consequently, Nick Rowe's reply to my post does nothing for me (although I still love the man and his blog!). On the other hand, I am not so sure about "sticky" nominal debt. I am more sympathetic to Evan Koenig's view:
The analysis presented here is completely orthogonal to the literature. It does not involve goods-market or labor-market pricing frictions in any way. As our most severe economic downturns have been characterized by widespread default on financial obligations and disastrous breakdowns or near breakdowns in lending, an analytical framework that puts debt and the distribution of risk at center stage arguably has something to say about optimal policy. 
One of the main proponents of NGDP targeting sent me this article, so I took it to represent a main theoretical justification for NGDP targeting. And indeed, a lot of people seem to be talking about a "debt overhang" problem and a "balance sheet recession." I sort of figured (perhaps incorrectly) that the idea of getting the Fed to commit immediately to (say) a 5% NGDP target was to generate a credible temporary inflation to reverse the effect of the unanticipated and sharp decline in the price-level path (in 2008).  The mechanism people have in mind, I think, is essentially to reduce the real debt burden of debt-constrained households, to get them to start spending, and to increase aggregate demand.

In my previous point, I raised the question of how strong and how desirable this mechanism might be now that we are 3 years out from the 2008 price level shock. Surely, a lot of the debt negotiated prior to the shock has been either reneged, renegotiated, or retired. At the same time, a lot of new debt has presumably been issued under the expectation of the new price-level path (given that people generally believe that the Fed will stick to its 2% inflation target). If the "turnover" rate is high (i.e., if there are large gross flows of debt being created and destroyed), and if the economy remains under "potential" for a long time, then one would have to question the quantitative importance of this mechanism; and also, the desirability of reversing the price-level path.

Well, I have to thank Mark Sadowski for taking the time to dig up some statistics for us. You can refer to the comments section of my previous post for details, but Mark's back of the envelope calculation is summarized here:
At the end of 2011, there was some $13.2 trillion in household debt outstanding. Of that nearly three quarters, or about $9.8 trillion, consisted of home mortgages  
... 
Thus a total of perhaps $5 trillion in debt has been originated/refinanced since the new NGDP trend has been established. Which means that about $8.2 trillion or approximately 64% was negotiated before the new trend was established. 
Assuming that the rate of origination/refinancing is linear (dubious) then it will take a least another five years before all household debt conforms to current NGDP growth expectations. 
So, it seems that there is still a lot of "old" debt out there, negotiated under the old price-level path. But there is also $5 trillion in new debt, negotiated under a new price-level path. And the longer we wait, the more this number will grow. Granted, this problem may have been avoided if the Fed went into the crisis with a credible NGDP target. But this is not the world we live in. What would Scott Sumner do right now? Who is he willing to make angry and why? Scott offers a hint here: Can we confident about the benefits of more NGDP?  
2. But does it still make sense to go back to the pre-2008 trend line? Probably not, recently I’ve been calling on the Fed to go about 1/3 of the way back to that trend line, and then start a new policy trajectory (hopefully explicit in this case.)
In any case, it seems that Scott believes that "more NGDP right now would modestly reduce the unemployment rate."  I confess that I am not entirely sure what mechanism he has in mind here. I really do need to read his 1000 blog posts on the subject one day!

I still have a lot of reading to do before forming an opinion on this subject. There were a lot of really good comments on my post that I haven't mentioned here--I need some time to think them through. Before I sign off though, some of you may be interested in these two links (h/t Prof J):

First, here is George Selgin: Wide off the mark, or, Nonsense about NGDP targeting. This seems like an extreme view, but I think it deserves some attention. 

Second, we have Mark Carney (Governor of the Bank of Canada) speaking here on why he believes a "flexible inflation target" is superior to an NGDP target. 

Well, I'm in a bit of a pickle...

I can't yet publish an interesting bug I hoped to share; I also don't want to rehash my earlier points about vulnerability trade, even as the debate has flared up again, thanks to the unfashionably late attention from Forbes and EFF.


So what I wanted to do instead is, once again, annoy the few remaining readers with my hobbyist work. Specifically, I wanted to showcase three things:


  • Omnibot, an interesting robot with a reconfigurable drivetrain,
  • Cycloidal drive, a mini-project to make an unorthodox type of transmission,
  • Adventures in CNC, my semi-humorous summary of my experiences with home manufacturing.


Sorry about that, and may the fortune be with you from now on!

Høyesterett legaliserer skjulte kostnader

Storebrand Banks advokat Kyrre Eggen gir oss i DN fredag et interessant innblikk i hvordan Høyesterett har resonert i Lognvik-saken.

Høyesterett finner for eksempel ikke grunn til å skille mellom investeringer finansiert med egenkapital eller lån. Sistnevnte har imidlertid en betydelig høyere kostnad. Kravet om et bankinnskudd for å få kjøpe opsjoner vil derfor innebære betydelige kostnader når kjøpet er lånefinansiert.

Om jeg forstår Eggen og Høyesterett korrekt så har imidlertid ikke finansieringen betydning fordi for en kjøper med gjeld så er et kontantkjøp i praksis lånefinansiert, og det er jo ikke selgers ansvar. I dette tilfellet ble imidlertid kjøpet muliggjort av bankens finansiering. Lognvik underskrev sågar en blankett spesielt laget for lånefinansiering av strukturerte produkt, og banken tok pant i produktet. Banken må derfor formodentlig ha visst at kjøpet var lånefinansiert.

Høyesterett mener også at det ikke er snakk om skjulte kostnader, men de totale kostnadene av opsjonskjøpet er verken oppgitt eller enkle å beregne. Uten oppgitte faktiske kostnader var det ikke mulig for kjøper å sammenligne med alternativer, for eksempel investering i andre typer opsjoner eller fond. Retten mener likevel at man ikke skal dekomponere avtaler for å se etter skjulte kostnader. Men det ligger i sakens natur at en oppsplitting er nødvendig for å avdekke skjulte kostnader. Hvis ikke ville jo ikke kostnadene være skjult.

Høyesterett later også til å tro at siden dette var en investering beheftet med usikkerhet var investor rett og slett uheldig. I en finansverden der man blir genierklært om man over tid klarer én prosent meravkastning, så kan imidlertid en investering som dette med kostnader på 100 prosent aldri være hensiktsmessig.

Jeg er ikke jurist, så det kan godt være at dommen er riktig. Det er imidlertid ingen ting i begrunnelsen som tyder på det.

Se også tidligere innlegg i denne saken

En ubegripelig dom

28. februar avgjorde Høyesterett at et samlet gebyr på 100 % av investeringsbeløpet ikke er urimelig. Dommen viser at selv høyesterettsdommere har problemer med å forstå strukturerte produkter.

I 2006 lånte far og sønn Halvor og Harald Lognvik til sammen 2,5 millioner av Storebrand Bank for å investere i et spareprodukt som bestod av et bankinnskudd og opsjoner. De risikable opsjonene kostet ca. tre hundre tusen, et beløp de ville tape i sin helhet om markedet gikk feil veil. De resterende 2,2 millioner ble satt tilbake på konto i Storebrand Bank til fast rente.

Det er ikke lett å forstå hva hensikten med dette innskuddet skulle være, bortsett fra å bidra til bankens overskudd. Det som er klart er imidlertid at Lognvik på alle områder og uavhengig av markedsutvikling ville kommet bedre ut dersom de hadde fått kjøpe bare opsjonene.

Siden det kun var opsjonene som hadde nytteverdi for investorene, er det mest relevant å sammenligne produktets totale kostnader med kjøpet av disse derivatene. I dissensen i Høyesteretts avgjørelse fremkommer det at de totale gebyrene til sammen utgjorde like mye som verdien av opsjonene. Flertallet i høyesterett kom likevel frem til at det ikke var urimelig at banken ved hjelp av et bokføringstriks påførte kunden kostnader som doblet prisen på investeringen.

Det mest interessante med denne dommen er selvmotsigelsene i flertallets syn. På den ene siden mener de at dette produktet var lett å forstå. Det står for eksempel: “Sett fra investors side fremsto produktet som oversiktlig”. På den annen side ser det ut til at rettens flertall har misforstått produktet og investors kritikk mot det.

Et stort poeng i denne saken er som nevnt at Storebrand Bank har lånt ut penger som så er satt tilbake på konto i samme bank. Dette er uten verdi for investor, men gir en ganske betydelig inntekt til banken. For å kunne frikjenne banken må man ha en god forklaring på hvorfor dette er greit.
Som svar på dette skjener flertallet ut med en argumentasjon som ikke har noe med saken å gjøre. Det argumenteres grundig og utførlig for at Storebrand Bank ikke kan kritiseres for at lånet ble tatt opp i samme bank. Faktisk ville investorene trolig betalt en enda høyere rente i en fremmed bank! Ingen er uenig i det, men hvilken relevans har det?

Faktum er at kunden lånte penger og satt dem inn på en konto. Det finnes neppe en oppegående person i Norge som synes at dette høres fornuftig ut. Storebrand Bank syntes imidlertid dette var en finfin investeringsstrategi. Som utsteder og långiver var den selvsagt fullt klar over at transaksjonen var både kostbar og unødvendig for kunden. Det ville ikke spilt noen rolle om en annen bank hadde vært långiver, så lenge Storebrand Bank var klar over at kjøpet ble lånefinansiert.

Problemet var et at et i utgangspunktet dyrt og dårlig produkt ble en ren parodi når det ble lånefinansiert. Banken kunne ha argumentert for at det fordyrende kravet om et innskudd ved kjøp av opsjoner var til for å hindre kunden i å påta seg for mye risiko. Når produktet ble tillatt lånefinansiert taper imidlertid denne forklaringen all troverdighet. Den eneste troverdige begrunnelsen for konstruksjonen blir da at den gav gode inntekter til banken.

Det er i det hele tatt vanskelig å begripe hvordan et produkt som er oversiktlig og enkelt å forstå kan være slik konstruert at tusenvis av mennesker låner penger for å sette dem i banken igjen. Den mest nærliggende forklaringen er at produktene slett ikke var så gjennomsiktig som Høyesterett skal ha det til.

Dessverre er det ikke nevneverdig prinsipiell forskjell mellom denne og de mange andre sakene om tilsvarende produkter. Høyesterett har ikke for vane å ombestemme seg i tide og utide. Med denne dommen er derfor løpet nå etter alt å dømme kjørt for de mange som uvitende har betalt overpris på sine investeringer.

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